The present invention relates to scroll machines. More particularly, the present invention relates to scroll compressors, which incorporate a unique two-piece suction inlet fitting.
Scroll type machines are becoming more and more popular for use as compressors in both refrigeration as well as air conditioning applications due primarily to their capability for extremely efficient operation. Generally, these machines incorporate scroll members having a pair of intermeshed spiral wraps, one of which is caused to orbit relative to the other so as to define one or more moving chambers which progressively decrease in size as they travel from a radially outer suction port toward a radially inner or center discharge port. Some type of power unit is provided which operates to drive the orbiting scroll member via a suitable drive shaft. The bottom or lower portion of the housing which contains the scroll members normally contains an oil sump for lubrication of the various moving components of the compressor.
Scroll machines can be separated into two categories based upon the positioning of the power unit which drives the scroll member. The first category is scroll machines which have the power unit located within the housing or shell along with the scroll members. The housing or shell containing the power unit and the scroll members can be open to the environment or it can be sealed to provide a hermetic scroll machine wherein the housing or shell also contains the working fluid to be compressed by the scroll machine. The second category of scroll machines is scroll machines which have the power unit separate from the housing containing the scroll members. These machines are known as open drive scroll machines and the housing which contains the scroll members is normally sealed from the environment such that the housing contains the scroll members and the working fluid being compressed by the scroll members. The power unit for these open drive scroll machines can be provided by a drive belt and a pulley system, a gear drive system, a direct drive system, or any other type of drive system.
Each of the above two categories of scroll machines can be further subdivided into two additional categories. These two categories would be scroll members which rotate on a vertical axis, and scroll members which rotate on a horizontal axis. Open drive type of scroll machines which have the power unit exterior to the hermetic shell are the most popular type of compressors with the rotational axis of the scroll members positioned horizontally. Both the compressors having the rotational axis of the scroll members positioned vertically and horizontally have similar issues and/or problems which must be addressed. One of these common problems is to control the amount of lubricant which is ingested by the suction port defined by the scroll members.
During the operation of the scroll machine, the lubricant is distributed to the various moving components of the compressor. In a compressor where most of the moving components are located within the suction chamber of the compressor, the lubricant in mist form is usually present throughout the suction chamber. The scroll members ingest the working fluid into their suction port along with a certain amount of the lubricant in mist form. The working fluid and lubricant are compressed by the scroll members and delivered through a discharge outlet to the components which make up the system using the compressed working fluid. Once the system has utilized the compressed working fluid, it is returned to the hermetic housing or shell through a suction inlet.
The present invention provides the art with a unique suction fitting. The fitting is located at the suction inlet of the compressor and is designed to direct the returning working fluid into the compressor""s working chamber. The fitting is formed by an outer powder metal suction plate which is disposed about a metal suction tube. The suction fitting is configured so the suction tube retains a fine meshed screen. Furthermore, the powder metal suction plate, which is used to couple the working chamber to a compressor""s working fluid return system, is not subject to any pressure gradients formed by a functioning compressor. The suction fitting is formed by brazing a powder metal suction plate in its green or unsintered state to a cast suction tube.
Other advantages and objects of the present invention will become apparent to those skilled in the art from the subsequent detailed description, appended claims, and drawings.